I've thoght about getting myself the os or tt .61 engine to put on my lanier dart .40 - .60. I don't have alot of experience with
planes yet ,but from what I've heard that should be enough power to take off on a shorter runway nice and smoothly.
What do you think ??? [&:] [8D].

Go with the 91 size engine because it is the same weight and much more power.

The best Thunder tiger engines are the 46 two stroke and the 91 four stroke. There are nicer 61's than the Thunder Tiger 61 that weigh a lot less.

But 61's seem to be a thing of the past anyway. No one talks of them on here anymore. OS came out with a 91 that's in the same case as their 61. Magnum/ASP came out with a new 91 that's in a case that looks just like the OS 61 engine. Super Tiger has a G90 that's in the same case as their G61. There's also a new Webra 91 that's in a small case. As well, there may be others?

Enjoy,

Jim

I suspect the Lanier Dart would shake apart with a .91. And actually a .91 is not a light as a light .61, as apposed the TT and OS .61. I would go to the Mecoa site www.mecoa.com and buy the K&B .61. More power than the TT .61 and much ligher.

Case in point....

OS 61FX = 19.4 ox without muffler

OS 91FX = 19.42 oz witout muffler

Super Tiger G61 = 19.96 oz without muffler

Super Tiger G90 = 20.66 oz without muffler

Magnum XLS 91A = 18.9 oz without muffler

Tower 75 18.9 oz

GMS 76 19.4 oz

K & B 61's = 14.25 oz

Os 46AX 13.2 oz

As wye8 said--the 2 really good TT engines are the 46 2stroke and the 91 FS.

The OS 61FX is not that big on performance either. It's a good sport engine--but it's no racehorse. And the darn thing costs $160.[:'(]

For the money, weight, and power--you might as well get a Tower Hobbies .75 engine. They cost $95 and they run like a raped ape. If your a Tower Super Saver Club member--then you got a 4yr warrenty[X(], and free parts shipping. Compare the weight of the .75 to all the 61 engines. It's crazy.

If you like ringed engines--you might do a search for the GMS .76 ringed and see how it stacks up.

I wouldn't touch an OS 91 2-stroke with a 20' pole. Just do a search here and you'll see why. For $200 the darn thing should run outta the box.

I wouldn't buy a 61 anymore. Just too heavy for the power you get.

The K&B 61 is the exception to the heavy rule. As noted in an earlier post, its weight is on a par with most 40-46 engines, and it's considerably more powerful.

An excellent engine choice for any 40-46 plane you want to make faster/sportier.

One example is my Diablo 40. With the K&B ringed 61 installed it will take off vertically from my hand.

And it's almost impossible to hurt it.

Bill.

PS: As you can see, it makes a neat installation. wr.

The Tower .75 rules the roost right now in the "below 90 size". It will whoop
up on most of the 90's....but on the other hand, it's not too good for torque
or 3D....it's a screamer.

FBD.

A few months back I wrote a feature in my column on the death of the .61 size engine. I believe the .61 is going like the .40. 20-30 years ago, everyone flew a .40 in their mid-sized planes. In the late 1970s, the OS .40FSR was THE engine to have. We all had them. After a few years they came out with the OS .45FSR. It took a while, but that extra power for a few bucks more caught on. Soon everyone was making a .45, then the newer generation engines started being called .46s.

I remember guys claiming they were always going to fly .40s, but that didn't last. Look, you can still buy an OS .40FX and a Thunder Tiger .40 Pro. Nobody buys them except for an unsuspecting few, I guess, but there are a few around for sale.

When they came out with the .75s and then the .91s in the same crankcase as the .61, the .61 was doomed in the long run. I just checked the price of the Tower .61 & .75. $5 difference. The GMS is probably close to the same. I don't know if Magnum even makes their .61 any more. I do know that when Magnum went to their new XLS series from the older XL engines, the first ones they made were the .46XLS and the .91XLS. With the .75 & .91 you can run a bigger prop if you want to or you can turn the same prop you run on a .61 at a higher rpm. So why, for the life of me, would anyone buy a .61???

Now I know there are guys out there who are going to say you can't beat OS reliability and they will fly their OS .61FX until someone tears it from their cold, dead hand. I'm sorry, I really am, but you remind me of my buddy with his .40. A Tower .75, or any of the other .75-.91 engines, will beat that .61 every time.

All true, Ed....and what can we say ? In a time when K&B doesn't have
replacement pistons for the 6550 .61 engine....their mainstay for years. [sm=stupid.gif]

When Magnum no longer offers their built like a tank .61's, and .75's.

It looks like the prospects for the .61's is dim, indeed. []

Dave.

Well, maybe they are not planning to make new parts for the 6550, they gotta stop sometime. However I suspect it is more RJl/Mecoa inefficiency. But they do have a more current ABC engine. Hopefully they will get on with its replacement and maybe a larger version as well. But I don't have much faith in RJL/Mecoa doing anything other than to keep making the same engines, and keep poor inventory of parts.

This collum reads like a social commentary on the demise of a certain size engine not an answer to the poster's question. If the engine size disappears so what? Some company will find a way to get .61 displacement into a .40 size case just lile they did with .50-.52s.
I am hearing that you as a group are say that .61 engines are not powerful enough for these crossover .40-.60 size planes. I have done tests on my thrust bench pulling 9.4 lbs of thrust from a 6" pitch prop from multiple OS 61 FX engines. The K&B Twister pulls well over 10 lbs static thrust on the same props. It seems like 10# of thrust is more than enough for a 6.5# airplane.
If it is flown on the wing, it can be expected to fly with a .40. If you want more try a .46-.50. The K&B weighs the same as most .46 size engines while providing more sport flying power than any of them. Last I knew the twister was selling at bargin prices, at least competetive to the tower units.

oneskyjoker,

Other very reliable, lightweight and powerfull 60-sized options are the Webra 61F ringed or the MVVS 61 ABC with tha latest carburetor.
Good luck

If want to have a powerful .80 engine with best price,take a look at
http://www.http://www.kangkeusa.com/.../skengines.htm
for only 69.77$ ringed ABC.

Turk1....this link works better than yours.

http://www.kangkeusa.com/Engines/skengines.htm

That engine looks like a good deal for the price, have you tried them ?

FBD.

Am I wrong when saying "ABC & ringed does not make sense" ???

Those SK engines are heavy, especially the .80. Again with the Lanier Dart I don't recommend anything other than a light weight .60 as that what was available when they were introduced, and they had problems with the ABS plastic cracking even with those engines.

ABC means ringless to me....genarally speaking. Ringed engines are mostly steel
liners, with the exception of the Saito's. There is usually an exception to just about
everything.

FBD.

I've got a Thunder Tiger 61 bushinged engine on my Lanier Dart. It is hands down the fastest plane in my fleet. 80-90 MPH on the straight and level. Although the Dart is old school ARF technology, it is still a super airframe. I scratch built different tail feathers for mine.

Dave: although this is a different discussion, the prevailing school of thought is that ringed is longer lasting while ringless ABC is more powerful but wears out much faster. Ringed ABC stays at peak longer than ringless while yielding better power than the old steel sleeve and ring design.

Thanks, Mike.....

....I prefer ringed engines myself. I will be running the .60's for the duration
of my time on this Planet....I love them, especially the OS 60 FSR's, the K&B .61
and the rear pipe OS .61RF pattern motors.

FBD.

FBDave,Yes, I bought one .80:Probably you have read my several comments on different threads.I run it on bench only to break in.
Its ringed. Visually clean.I removed backplate by recommendations to check any manufacturing debris,Not any debris at all.Clean.I roughly opened the needle valve(3.5 4 turns) and adjust the idle valve rougly by blowing by with a silicone method.With a no nitro, 20% castor self mix fuel,it started with the first flip after some priming.Plug is OS no 8.Very powerful running,almost run out of the bench,nearly costing one finger to me.
It seems running good on bench.Some slight sticky throttling during mid throttles,I guess maybe carb freezing effect.
I think will be a good plant on a future plane too.

Turk....that looks like a decent engine, and the price is right. [sm=thumbup.gif]

It's hard to see the detail on the carb, does it operate OK ?

Dave.

FBDave, I have read some sticky .50 SK carb complaints, so first thing I have done to excersize the carb with manually many times to detect any similiarity.Not at all.Also I apply some Molycote on throttle barrel as precaution.Never got any sticky move until I run it on bench and after some full throttle application following after minor throttling excersizes.Never sticky before but after full throttling.Immediately gone after stops everytime.I dont think it will be a problem on a plane but must be careful sure.
BTW I placed an order for a SK .50 ABC BB. engine today.I hope I can report on it too.I have a trainer for it.

That's why I was asking....I have seen some poor workmanship on the
carbs from some of the Chinese offerings. I'm sure they'll improve as time
goes on....but the hand machining can be sub-standard, resulting in
sticky barrels and such. I like the Chinese engines because they're prices
and parts prices are low, which is good. The japanese are pricing themselves
out of the market. []

Dave.